Ogert Robert A, Wojcik Lisa, Buontempo Catherine, Ba Lei, Buontempo Peter, Ralston Robert, Strizki Julie, Howe John A
Schering-Plough Research Institute, Department of Biological Sciences-VIROLOGY, K-15-4945, Kenilworth, NJ 07033, USA.
Virology. 2008 Apr 10;373(2):387-99. doi: 10.1016/j.virol.2007.12.009. Epub 2008 Jan 10.
Several small molecule drugs that bind to the host CCR5 co-receptor and prevent viral entry have been developed for the treatment of HIV-1 infection. The innate variability found in HIV-1 envelope and the complex viral/cellular interactions during entry makes defining resistance to these inhibitors challenging. Here we found that mapping determinants in the gp160 gene from a primary isolate RU570-VCV(res), selected in culture for resistance to the CCR5 entry inhibitor vicriviroc, was complicated by inactivity of the cloned envelope gene in pseudovirus assays. We therefore recombined the envelope from RU570-VCV(res) into a highly active and susceptible ADA gp160 backbone. The chimeric envelopes generated robust signals in the pseudovirus assay and a 200 amino acid fragment, encompassing a C2-V5 region of the RU570-VCV(res) envelope, was required to confer resistance in both the single-cycle assay and in replicating virus. In contrast, a chimeric envelope that contained only the V3-loop region from this resistant virus was completely susceptible suggesting that the V3-loop changes acquired are context dependent.
几种与宿主CCR5共受体结合并阻止病毒进入的小分子药物已被开发用于治疗HIV-1感染。HIV-1包膜中存在的固有变异性以及病毒进入过程中复杂的病毒/细胞相互作用使得确定对这些抑制剂的耐药性具有挑战性。在这里，我们发现，从在培养中选择对CCR5进入抑制剂维克立罗克耐药的原代分离株RU570-VCV(res)的gp160基因中定位决定因素，因克隆的包膜基因在假病毒试验中无活性而变得复杂。因此，我们将RU570-VCV(res)的包膜重组到一个高活性且敏感的ADA gp160骨架中。嵌合包膜在假病毒试验中产生了强大的信号，并且在单循环试验和复制病毒中都需要一个包含RU570-VCV(res)包膜C2-V5区域的200个氨基酸片段来赋予耐药性。相比之下，仅包含来自这种耐药病毒的V3环区域的嵌合包膜完全敏感，这表明获得的V3环变化是依赖于背景的。
